Cooling system for internal-combustion engines



March 11, 1947. E. F. CHANDLER 23 9 COOLING SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Jan. 31, 1945 IN VENTOR.

Patented Mar." ll, 1947 UNITED STATE COOLING SYSTEM FOR INTERNAL- I COMBUSTION ENGINES Edward F. Chandler, Brooklyn, N. Y. Application January 31, 1945, Serial No. 575L498 14 Claims.

cooling the engine lubricating oil. Sea water iscirculated through these heat exchangers as the coolant, the usual arrangement providing for series flow of the sea water, first through the lubricating oil heat exchanger and thence through the jacket water cooler.

A somewhat less common engine cooling system provides for cooling the engine jacket water, as described above, but instead of circulating sea water through the lubricating oil cooler, the cooled jacket water is employed as thecooling medium. This type of cooling system has the advantage of exposing only one of the two heat exchangers or coolers to the corrosive action of sea water, and .the further advantage that, upon starting a cold engine, the engine and the lubricatin oil and the jacket water temperatures are elevated to the proper operating temperature range much more rapidly than when the colder sea water is circulated through the lu-' bricating oil cooler. This type of cooling system has the disadvantage of requiring the use of somewhat larger heat exchangers for a given installation, which, to some extent, offsets the advantages derived therefrom.

However, the advantage obtained by circulating jacket water through the lubricating oil cooler, that is to say, the'initial rapid heating of the engine lubricating oil and maintenance of optimum lubricating oil temperature during operation, has become extremely important in view of current operations of Diesel engine propelled naval vessels in the Northern and Southern cold sea areas. Reports show that, in many cases, the chilled engine lubricating oil in vessels operating in these areas, and not equipped for jacket water circulation through the lubricating oil coolers, never reaches the proper operating temperature'even after hours of engine operation, resulting in accelerated wear of all bearing surfaces, early engine failure, decreased reliability,

high-speed Diesel engines, and it has been deflnitely established that engine deterioration is very rapid whenever operation proceeds with either lubricating oil or jacket water circulating at a temperature below 130 F.

The principal object of the present invention is to avoid the difiiculties encountered by the use of sea water circulating through the lubricating oil cooler, and to take maximum advantage of circulating jacket water through such cooler for rapid heating of the chilled lubricating oil upon forautomatic control of the temperatures of the starting cold engines, and,' in addition, to provide for automatic control of the temperatures of the lubricating oil and jacket water within the optimum operating range, as specified by the engine designer, regardless of variations in the power at which the engine is operated, or variations in the temperature of the sea water. With these and other objects in view, as well as other advantages that may be incident to the use of the improvements, the invention consists in the parts and combination thereof hereinafter set forth and claimed, with the understanding that the several necessary elements constituting the same may be varied in proportion and arrangement without departing from the nature and scope of the invention, as defined in the appended claims.

In order to make the invention more clearly understood, there are shown in the accompanying drawings means for carrying'the invention into practical use, without limiting the improvements in their useful application to the particular'construction, which, for the purpose of explanation, has been made the subject of the illustrations.

and excessive maintenance and repair require ments. This is particularly true in the case oi! Fig. 1 of the accompanying drawing is a diagrammatic -view of a system ofautomatically controlling the temperature of the lubricating trolling the temperature of the lubricating oil and jacket water of an internal combustion engine is shown as comprising, generally, an engine I, a jacket water cooler 2, and a lubricating oil cooler 3. The jacket water cooler 2 is provided with a heat transfer element 4, through which sea water is circulated from pipe 5 and 3 valve 6, and f1 om which the sea water escapes through pipe I. This cooler is also shown as provided with a heat transfer element 8, through which jacket water to be cooled is supplied from the engine. The cooled jacket wates escapes from the heat transfer element 8, through pipe 9, in which is positioned a thermal-responsive control element IG. The element In is preferably adjustable to function at a predetermined temperathe heat exchange element l1, situated in the cooler 3, the escape end of said element being connected with pipe 14. A by-pass pipe l8, connected at one end with the valve I6, connects with pipe l4. Lubricating oil is circulated from the engine I through pipe 20, through the heat exchange element 2|, and back to the engine through pipe 22. In the by-pass pipe 23, a pressure-relief valve 24 may be provided. Situated in pipe 22 is an. adjustable, thermal-responsive element 25, which, through suitable means 26, is adapted to control the valve I6 in response to changesin the temperature of the lubricating oil in pipe 22, so as to increase or decrease the flow the means in pipe 3, said means l0 being thermally influenced, for example, by the temperaof water in the by-pass pipe l8. For simplicity,

temperature and pressure-indicating means, and

other auxiliary equipment common to systems of this order, have not been shown in the drawing.

Valve 6, which may be manually or automatically operated, serves to control the quantity of sea water passing through the element 4 in cooler 2. If desired, the same purpose may be served by the provision of a circulating water by-pass around this cooler. Lubricating oil from the engine may also be by-passed around the lubricatpipe 23 can be arranged to by-pass other parts of the engine lubrication system as well as the heat exchanger 3, such as lubricating oil filters, strainers, etc. a

In operation of this improved system, upon initally starting the engine, and with the engine in operation, the jacket water is rapidly heated, and this heated water directly enters the heat exchanger 3,- providing for rapid heating of the chilled lubricating oilcirculating through the oil heat exchanger.

In this connection, it will be understood that in most types of internal combustion engines, the amount of heat dissipated into the jacket water by the operation of the engine is about ten times the amount of heat dissipated into the lubricating oil. Therefore, the jacket water is heating very much more rapidly than the lubriter cool ng is governed by heat exchanger 2. In

the preferred method of operating this system, as

the jacket water temperature becomes elevated to the operating range, the flow of heated water being returned to the engine through the byture of the water flowing in pipe 9, to actuate valv'e II, to reduce the flow through the by-pass pipe l3, thereby increasing the flow through the cooler 2 and reducing the temperature of the water being returned to. the engine through pipe 3.

By this means, sufficient jacket water is forced through the cooler 2 to maintain a constant pre. determined temperature of the jacket water re-- gardless of the temperature of the sea water cir-' culating through the jacket water cooler, and regardless of variations in the power being generated by the engine. Indicating the'thermal-responsive element III, as positioned in pipe 9, is optional, as a similar efl'ect, i. e., the control of valve II in response to changes in the temperature of the circulating jacket water, may be obtained by placing the element III in pipe 14 beyond the connection thereto of byt'DaSS pipe I3, or in pipe l5 at a point preferably between the engine and the valve l6.

With a substantially constant temperature maintained in the jacket water leaving the engine through the operation of the temperature control valve ll, causing more or less heat to be released by the heated jacket water, it will be noted thatat any given engine power, the temperature of the jacket water and lubricating oil circulated to and from the engine remains substantially constant, regardless of all changes in the temperature or quantity of the sea water circulated through jacket water cooler 2. This is apparent by reference to the drawing. At constant engine power, heat dissipated to and from the oil and jacket water in the engine and the heat exchangers or coolers is substantially constant. Therefore, with a constant engine jacket water discharge temperature, the temperature of the jacket water entering the engine is substantially constant, because the rise in temperature of the water flowing. through the engine is constant. Thus, the temperature of the jacket water leaving the lubricating oil heat exchanger 3 is constant, and as the amount of heat dissipated to the jacket Water from the lubricating oil in the lubricating oil heat exchanger is constant.

the temperature rise of-the jacket water and lubricating oil to and from the lubricating oil heat exchanger remains constant. Thus, regardless of changes in the temperature and quantity of the sea water, theoil and the jacket watertemperatures to and from the engine are maintained substantially constant at any given engine power, which is a very desirable engine operating condition from the standpoint of engine service life and reliability.

By properly proportioning the size of the heat I exchangers, and by suitably adjusting the automatic control means, it is possible to provide for cooling the lubricatingoil flowing to the engine to a temperature as low, or even'lower, than the temperature of the jacket water flowing to the engine. Also, the system renders possible a minimum temperature rise of the jacket water flowing through the engine, which is very desirable for certain types of engine installations Referring to Fig. 2, which illustrates a modification ofthe system above described, it will be noted that a by-pass pipe 30 connects with the return jacket water pipe 9, preferably above the thermal-responsive unit ID, the other end of said pipe 30 being connected with the jacket water delivery pipe l5, preferably near its inlet, to the heat exchanger 3. It will be noted that this v y-pass pipe II is adapted to deliver jacket water which has been cooled by the cooler '2 into the stream of heated jacket water leaving the engine I through pipe ii, to blend therewith and to thereby modify the heat of the jacket water leaving the engine, and to re-circulate the admixture back through the heat exchanger 3 and the cooler 2.

The flow of water through the by-pass 30 is preferably governed by the temperature of the lubricating oil being circulated through the engine, and for that purpose a suitable three-way.

control valve 3|, operatively connected by suit-.

'able means 32 with the oil temperature responsive governing means 33, may be employed. I Said means 33 ar indicated as connected with pipe 20,

and adapted to be influenced by the heat oi the lubricating oil leaving the engine therethrough,

but the same may be inserted in the lubricating oil return pipe 22, or otherwise situated to accomplish the desired purpose. The by-pass pipe I8,

and the means responsive to the lubricating oil temperature for controlling the flow of jacket water therethrough, are not shown in Fig. 2. It is to be understood, however, that the same may be incorporated therein, and further, that parts and combinations of parts of the system shown in either or both drawings may be interchangeable, depending upon the results it is desired to accomplish.

It will be noted that the by-pass 30 afiords an efflcient means for increasing the temperature difierence between the fluids flowing through the heat exchanger 3, making it possible to readily increase ,or decrease the heating of the lubricating oil in close response to the automatic, thermal governing means. The adjustable valve 3! may be of the proportioning type, and preferably adapted to permit only a portion of the jacket water leaving the cooler 2 to be by-passed, to insure a suflicient flow of co'oled jacket water to the engine. Element Ill in the system, shown both upon starting a cold engine, and the rapid warming up of a cold engine upon starting. The temperature of the jacket water and lubricating oil is controlled entirely automatically. The lubricating oil heat exchanger is not subjected to' the corrosive action of sea water. The improved system permits of simplified piping arrangement and the control of the temperatures of both the ja ket water and lubricating oil by simple. automatic governing means. The system has the additional advantage of providing for relatively small temperature rise of jacket water circulated through the engine with minimum size of lubricating oil heat exchangers.

It will be understood that, whereas the above description of the present engine cooling system is particularly adaptable to marine engine installations, it is equally applicable to all other internal engine installations. For land installations, the term sea water," as employed herein, may be more properly termed cooling water or a cooling fluid obtained from an external source, and for aircraft installations the primary cooling medium may be air.

It will be' -understood, as previously stated, that the above description and accompanying drawing comprehend only the general and preferred embodiment of the invention, and that various changes in construction, proportion and arrange- .ment of the parts may be made within the. scope of the appended claims without sacrificing anyof the advantages of the invention.

What I claim is:

1; A system for controlling the temperature of the cooling water and'of the lubricating oil of an internal combustion engine, including'an internal combustion engine, a first heat exchanger for governing the temperature of the engine lubricating oil, a second heat exchanger for cooling the engine jacket water, means for circulating lubricating oil from the engine through the first 2. A system for controlling the temperature of the cooling water and that of the lubricating oil" for an internal combustion engine, wherein a first heat -exchanger through which lubricating oil from the engine is circulatedcools the water flowing from the engine, and a, second heat exchanger is adapted to further cool said water, the heat transferring capability of the first said heat exchanger being governed by the water flowing from the second exchanger, controlling the temperature of the said lubricating oil, characterized by the fact that there is combined with the first said heat exchanger means governing the quantity of heated water flowing from said engine cooling system through said second heat exchanger and being admixed with water from the first said heat exchanger for delivery to the engine in a heated condition in order to elevate the temperature of the lubricating oil.

3. The method of controlling the temperature of the cooling water and that of the lubricating oil of an internal combustion engine, which comprises subjecting the lubricating oil in a flowing stream in indirect heat exchange relationship to a flowing stream of cooling water, simultaneously subjecting said stream of water in indirect heat exchange relationship to 'a flowing stream of coo ant fluid ata temperature below that of. said cooling water, and returning the cooling water thus treated to the engine for recirculation.-

4. The method of controlling the temperature of the jacket water and that of the lubricating oil of an internal combustion engine, which comprises subjecting the lubricating oil in a circulating stream and in indirect heat exchange relationship to a circulating stream of jacket Water,

. whereby the temperature of the lubricating oil is raised, subsequently subjecting the circulating stream of jacket water in indirect heat exchange relationship to a circulatingstream of cooling fluid, and then returning the jacket water to the engine.

heat exchange relationship to the water circulating through the zone of lesser cooling, and rethe cooling water and that of the lubricating oil of an internal combustion engine, which includes a heat exchanger through which the cooling water of the engine is adaptedto be circulated, means for circulating therethrough lubricating oil from the engine and in indirect heat exchange relationship with the circulating cooling water, and means controlled by the temperature of the jacket water and that of the lubricating oil of an internal combustion engine, which comof the lubricating oil for by-passing cooling Water around said heat exchanger.

7. A system for controlling the temperature of the jacket water and that of the lubricating oil of an internal combustion engine, which includes a first and a second heat exchanger, means for circulating jacket water from the engine through said heat exchangers and back to the engine, means for circulating lubricating oil from the engine through the first heat exchanger and back to the engine, and means governed by the heat of the water leaving the second heat exchanger for by-passing water leaving the first said heat exchanger around the second heat exchanger, and returning the same directly to the engine.

8. A system'for controlling the temperature of the jacket water and of the lubricating oil of an internal combustion engine, which comprises a heat exchanger through which lubricating oil from the engine is circulated, a jacket water cooler, means for circulating water from the engine through the heat exchanger and cooler, and temperature controlled means governed by the heat of the lubricating oil for by-passing jacket water around the heat exchanger.

9. A system for controlling the temperature of the jacket water and that of the lubricating oil of an internal combustion engine, which includes a lubricating oil heater and a jacket water cooler, means for circulatingjacket water from the engine through said heaterand said cooler and'for returning the same to the engine, means for circulating lubricating oil from the engine through said heater and back to the engine, and means governed by the heat of the lubricating on being circulated controlling the temperature of the jacket water leaving the engine.

10. A system for controlling the temperature of the jacket water and that of the lubricating oil of an internal combustion engine, which comprises a heat exchanger through which lubricating oil from the engine is circulated, a jacket water cooler, means for circulating jacket water from the engine through the heat exchanger and cooler, and temperature controlled means governed by the heat of the lubricating oil for by-passing jacket Water around the engine.

, 11. A system for controlling the temperature prises a heat exchanger through which lubricating-oil from the engine is circulated, a jacket water cooler, means for circulating jacket water from the engine through the heat exchanger and cooler, and means controlling the heat transferring capability of the heat exchanger including thermally-governed means for by-passing water from said cooler, around the engine, for recirculation through the heat exchanger.

12. The method of controlling the temperature of the jacket water and that of the lubricating oil of an internal combustion engine, which comprises subjectin the lubricating oil in acirculatingstream and in,indirect heat exchange relationship to a circulating stream of heated engine jacket water, subjecting the heated jacket water a in a circulating stream and in indirect heat exchange relationship to a circulating stream of coolant fluid, whereby the jacket water is cooled, passing cooled jacket water through the engine and then back.to said heat exchange relationship with the lubricating oil, and simultaneously by-passing cooled jacket water around the engine and into the stream of circulating jacket water leaving said engine,

13. A system for controlling the temperature of the jacket water and that of the lubricating oil of an internal combustion engine, a heat exchanger, a jacket water cooler, means for,circulating jacket water from the engine through the heat exchanger and the cooler to the engine, means for circulating jacket water from the cooler back to and through the heat exchanger, and means for circulating lubricating oil from the engine through the heat exchanger.

14. A system for controlling the temperature of the jacket water and that of the lubricating oil of an internal combustion engine, a heat exchanger, a jacket water cooler, means for circulatin jacket water from the engine through the heat exchanger and the cooler to the engine,

means for circulatingjacket water from the cooler back to and through the heat exchanger, means for circulating lubricating oil from the engine through the heat exchanger, and means for bypassing jacket water from the engine around the heat exchanger to the cooler.

EDWARD F. CHANDLER.

REFERENCES CITED The following references are of record in the file of this patent:

Woods Feb. 24, 1942 

